Pages

Tips

Please take your time and read the blog rules

May 20, 2013

Accuracy explained - WG dev on 0.8.6

Source: http://world-of-kwg.livejournal.com/195759.htmlSS: Pavel Myreev aka "Zlobny" is one of the WoT developers. His nickname might be familiar to the European supertesters - he is leading the supertest program as far as I know. The translation - as always - is at some points redacted for better comprehension in English. Also, I am neither physicist, nor mathematician, so I hope I don't get the English mathematics terms wrong. If I do, feel free to correct me. First, a bit of background though. There was another post (which the developer is referring to) - that "another post" is basically the translation of what was published in English - you know, that "leaked" post, that appeared on saturday night or something. I recommend to all of you to read it (if you haven't already), so you know what Zlobny is talking about.Well, here goes:
Currently I am working on the British artillery.

First I want to say that there is no need to write a lot of questions - think first and ask later - I am not a community moderator or producer, I have to work.

Limiting the aim spread to 1,3 standard deviations before 8.6 (SS: explained here) had, in my opinion, very bad influence on gameplay in general. The principles are generally known I think. When the management decided to change it, I started to think about possible variants of implementing this.

Unfortunately, the first variants were very raw and presumed an "accuracy nerf" of all the vehicles in the game. I was still inclining to the 3-sigma limit variant and not even meetings with Michale Zhivets (Storm) and Maksim Bladyko (chief server programmer for World of Tanks) convinced me otherwise. But in the morning before a very important meeting on this topic in Minsk, I went for a walk and as it happens, it wasn't in vain. It became clear to me that the 3-sigma limit has several significant weakenesses, apart from the increased spread distribution for all the vehicles in game:

- since the difference between 2-sigma and 3-sigma is only 2,14 percent, there will be mods made immediately depicting the aim circle as 2-sigma. After all - why wait for the fully accurate aim circle from 3-sigma and give the enemy more time to cope with you, when the difference between 3-sigma and 2-sigma is so small?

- the distribution will still focus on the center and the accuracy nerf, which I assumed to implement until that morning, won't suffice. If Storm went to the meeting with that solution, it would result in a fail (and bad karma for me).

So I called Storm in panic and told him that our solution sucks. But - as it often happens - the second I said it, another solution came to me by itself.

When considering shooting in our game, the difference between 1,3-sigma and 2-sigma is not all that great and - connected with a camo factor change it might not be even spotted by our players, because the effective battle distance will increase (more on that further on). The solution to fix it with one more sigma (between 2 and 3) came by itself from the previous meetings with Maksim and Misha (Storm).

But some players (SS: arty players) won't have their effective battle distance increased, so these players had to recieve a spread radius modifier. The value of this modifier was discussed by us and Dmitry Dragunov (aka Marschig), who represented the arty players' interests. After the supertest testing, I still think that 50 percent represent a rather small buff (!) of accuracy for arties. On the nerf of arty I will post further.

SS: at this point there is a table posted in the original post. What it means is percentual chance for a shell to drop inside the aim circle (within its borders, not ON the borders or outside them (which gets "normalized") to drop on the borders):

SS: the meaning of this table is - first column are the parts of the aiming circle, with the last line being its border. Other columns are: Old system (how it is now), 2-sigma and New system (0.8.6+). In other words, right now, you have a 19,36 percent chance of the shell going on the borders of your aim circle, in the new system, you will have only 0,27 percent chance of aiming for the aim circle edges. Another example: today, you have 48,43 percent chance of your shell going to the inner half of the circle, in 0.8.6 it will be 70,41 percent.2) Vehicle camo changes

Our camo system with multiplying visual camo coefficient and camo net coefficient has one big disadvantage, as all the systems such as this do: increasing size of the vehicle very quickly decreases the effectiveness of such devices. The decision to replace the multipliers with addition (SS: as in by adding some value instead of multiplying with it) was taken already in 2010-2011 by me, Maksim Bladyko and Pasha Vasilev (server structure architect for World of Tanks), but back then there was no visual camo coefficient (5 percent), so we didn't do it. This topic was brought up repeatedly in 2012 by L.Zacharchenko, chief game-designer for World of Tanks. Gradually, a snowball turned into an avalanche, which in the end was the reason for plans for the complete camo system rework.

I alread wrote enough letters, but basically we did the following:

- reworked all the camo factors in the game, based on the reference tanks (T-4, T-34) (SS: here, Zlobny probably means Panzer IV, not sure) and on extreme cases
- reworked the influence of shooting on camouflage, based on how it was before, but under the new system, so the "I just shot" negative modifier will be subtracted in the equation, rather than multiplied as it was now
- reworked the camo factor of camo net and visual camo based on the type of the vehicle (not individual vehicle, as it was before)
- reworked the camo bonus for bushes. This is a big topic, so a short version only: currently, maximum bonus from the bushes can be in 0.8.6 obtained by 4 thick bushes, instead of 2 not-thick bushes (pre 0.8.6). Furthermore, the exploit of firing thru the "non-transparent bushes" (skilled players will know about this and others don't really need to know) will be fixed completely. It is also worth noting that the battle (engaging) distance will increase by 15-20 percent.

A collossal amount of work was done on this, there were many tests and I really like the final version.3) Penetration change

A very painful topic for me, I did that only very reluctantly. Generally it turned out better than I expected, I won't write much - you all saw the numbers.4) Arty nerf

We did that together with Dmitry Dragunov, he fought for every split percent because I fear that we didn't nerf it enough, but I am generally satisfied by the numbers we sent to the supertest.

I wanted to make arty into a more complicated class with less possibility to fight on very short distances without diminishing the influence of the arty on combat there, where it is needed. New vehicles fit in very well, but I had some issues with SU-122A and M44.

XP buff wasn't done by me, thus I won't comment on that.

SS: Well, that's it. As always, a summary of info from the comments, given by Zlobny and others.

- camo skill won't be reworked (they decided it's not needed: "camo skill is more about positioning the tank by the crew better, but even if you position better, a Maus is still a Maus")
- vehicle camo factors won't be disclosed, but from now on, they directly depend on vehicle size and class (can be estimated by sight)
- camo skill will remain useless on big vehicles
- it's possible American vehicles will be rebalanced in 8.7

im very interested by that aim dispersion nerf of arty guns, because i just got one shooted by a fucking exactly after it turned its face to me. He didnt even waited for aim. Not even FV215 183 has that fucking crazy accuracy. A slight gun movement and the reticule is huge.

Sometimes it does miss. Even at point blank range. I have had it happen in a StpZ II and luckily, I had just enough time to reload and fire a second shot but in the process I lost half my health. Sometimes it does not end so well.

Lol most people who think that the m 18 is op are those that play it . Unlike some tanks that have very visible strengths (derp guns , troll armour) .M18 is not considered op cause when you shoot it it gets hurt it dies :P. But the one driving it sees the after battle report and can see much damage he put out .Paper armour lol it.. has a black hole on it's gun mantel where shells go do nothing and are never seen again :P

if we have gun with accuracy 0.5 then on the distance of 200 metres normal deviation will be 1 m and radius of the circle 1.3m

with new solution and limit 2 sigma how huge will be the radius of the circle?Sounds to me it will be 2 metres (if not, then we have all round accuracy buff with change in notation to cover it)

So in SS's example (shooting into half of the circle) in 0.8.5 we have 48% chance to hit into 0.65 m radius from aiming point.In new circle 0.65 m will be only 32% of circle size - and we can see from the table that new system gives 46% to hit into 0.3 of circle size.

So.....The only way I can see to make it understandable to me is an assumption:Gun accuracy is a radius of the aiming circle and 1 sigma is 1/1.3 = 77% of listed gun accuracy

in 0.8.6 aiming circle stays the same in size but sigma gets reduced to 50% of listed gun accuracy

Assuming for artillery accuracy change is roughly extra 50% then we can make such table for a situation where old aim circle has 10 metres radius:0.8.5 -> 0.8.63m: 30.35% -> 31.94%6m: 56.46% -> 59.34%9m: 75.80% -> 79.55%

so in approx 81% shots arty will now shoot slightly closer to the center then previously.But this 19.36% shots that currently hit exactly the aiming circle will now land outside of the old landing circle.

so if I understand correctly below graph applieshttp://wstaw.org/m/2013/05/20/accuracy_1.jpg

(horizontal scale - how far from aiming point shell lands, vertical scale - probability shell will land here or closer)

This looks about right. Going from that it appears that (assuming that all nerfs to arties are applied equally to every one of them) the most accurate arties (ie. ones that could fit the entire aiming circle, borders included, on target) will be hit the hardest while anything else will be only slightly nerfed.

It's possible. Hungarians also recieved a number of Panzer 38t tanks, which were redesigned as T-38. Funnily enough, Hungarians did also capture a number of T-38 Soviet amphibious tanks and both got confused (even in real life).

I can see some US tanks needing nerfs, and others that can handle a nerf. t57, is one that NEEDS the nerfs, to much damages compared to its peers. E5 could handle a nerf, and other uber hulldown tanks can take some changes. None are OP(besides t57) but i don't see any issues with the other lines or tanks in the US branch.

OP tanks needing nerfs:-M4 and Pz4 derpers.-T57-ridiculous RoF, pen and damage-KV-1S for the 122mm stupidity cannon-Hellcat for the super speed and firepower.-Type 59 for the gun/armour combo at Tier 8.

I agree with that list for the most part. The only dissenting opinion I offer is for the Hellcat; the lack of armor coupled with the slow turret rotation and the AVG ROF on the top gun more than compensate for the speed of the tank and the DMG it applies.

last post proves the point of the post he replied to and almost certainly is one of those snobs who thinks any tank he owns isn't OP. Typical type of response from a stat snob.Type 59 is OP which is why is NOT available anymore. What a pratt.

Type is OP... but only as a premium, which should be worse then a normal tank but type is close to the same in performance then a normal tier 8 med, that's why its not available in shop.

As long as they stop selling it theres no need for nerfing. As a Tier 8 tank its more then OK easy to pen Hull (if u know how to aim), good turret armour, average gun and average to bad acceleration (for a tier 8 med)

Any tank you don't have is OP. Not the other way around. I actually hate driving the Type because of the bad aiming time and bad gun depression. Plus, if people do have trouble penetrating the Type, they generally load gold ammo.

There are many weakspots on the Type. Just look up a Youtube video or something if you can't learn yourself instead of calling me a snob because I know my tank better than you do.

Essentially, the accuracy change will make accurate guns more reliable (less shells all the way to the edge) while making shots that "shouldn't hit" less probable due to less concentration towards the middle, thus discouraging half-aimed shots and sniping with derpy cannons.

If they don't nerf the accuracy on non-arties, which they apparently aren't doing, then there actually will be bigger concentration in the middle so half-aiming and inaccurate derps will actually get an accuracy buff.

I'm a bit confused on the accuracy changes and that table. I thought we are getting the 2 sigma table (middle column), and the right column looks like a 3 sigma breakdown, which we are not getting. Zlobny even says he didn't like the 3 sigma system because people would just mod the aim circle to show 2 sigma since statistically that is good enough.

I'll try to give explainWe have probability of getting shorts in parts of circle in each column (old one, 2 Sigma, new one). As you can see in new one we have percentage a bit higher then in 2 sigma. So let me explain why (I got it on one of the RU forums). Basically what we have is that about 5% of shots are going outside 2 sigma so developers need to do something with it. What actually they are doing they are evenly distributes them in the aiming circle so the whole curve of the normal distribution is getting bumped a bit.

I know about shooting thru non-transparent bush after spotting from transparent bush... The hell they gonna do to the bushes? They offer percentual camo behind the bush? So you can spot tanks even behind multiple bushes far beyond it even if fully behind it?

This would be fucking big mistake... Bush is bush and should stay as one... I don't like Maus being spotted from 400m in a forest... because it has 0 camo... ok close to it.

The non-invible bush effect, or double bush effect, is the camo calculation for having two bushes in a row between you and the enemy.After firing, only the closest bushes lose their camo bonus, while the second bush is unaffected. That means firing will not reduce your camo bonus, leading to invisible snipers from 150m.

I've yet to experience this, because if the bushes ahead of me aren't non-transparent, I get spotted. Period. And I've played the game for 20k for 60% success rate... So there most likely are bugged bushes or something cause I've yet to see this one.

" Furthermore, the exploit of firing thru the "non-transparent bushes" (skilled players will know about this and others don't really need to know) will be fixed completely."

Great... Now they remove one of the best noob-bashing feature that allowed good players to be good along with some other tricks. Now bushes will be only good for the 10- WN guys that camp all battle in a bush without firing. There are only a relatively small amount of tricks that can separate a good player from a bad... And now they want to take those out too... How can someone be good, when there is NO ARMOR (cough cough GOLD cough) and NO CAMO?!?!!? Bushes lost their meaning in my eyes...

"maximum bonus from the bushes can be in 0.8.6 obtained by 4 thick bushes, instead of 2 not-thick bushes (pre 0.8.6)"

Then add more f***g bushes god dammit!There are only a few maps where you will find 4 good bushes in a row to hide behind... BS!

After every patch my favorite vehicles are nerfed to ground, my favorite features are deleted.

After every day of playing i get closer to uninstalling permanently and looking for something else...

"4) Arty nerfWe did that together with Dmitry Dragunov, he fought for every split percent because I fear that we didn't nerf it enough, but I am generally satisfied by the numbers we sent to the supertest."

Nice to know that at least one of the devs is trying to better the game. The current ability of the "indirect fire support" class to consistently nail tanks dead-on for massive damage has long since gotten old.

Maybe, just maybe, the decrease in accuracy will allow people to actually play the game and use terrain to its fullest, instead of having to constantly hide behind rocks/select buildings in fear of a bullshit oneshot from a "skilled" player camping in the back of their base clicking dots on the GPS map.

I love playing my GW Panther, but oneshots? Very, very rare. And the GW Panther is one of the most, maybe even the most accurate SPG in the game. I do a lot of direct hits, but oneshots are still extremely rare.

GW Panther has a weak gun compared to other arties of this tier so mostly it does 300-400 dmg per direct hit but it got the accuracy to compensate for it...Its with bigger guns with less accuracy(gw tigers, t92s and so on) where rng comes to play. Mostly you do just splash damage but if you get lucky(which is bad for gameplay it shouldnt be about luck) and you hit directly your foes you hit them for 1000+dmg quite reliably(especialy the no armour ones) and posibly killing them in one shot. But in most cases it happens becouse of player stupidity(batchat in the open not moving for 10s is a nice target) but whiners will whine whenever they feel like it. 5 arty matches are bit problematic but you got to remember that your team have arty aswell.

What an abuse of the word "camping". That was originally a Quake term denoting players waiting for others to appear. In a tactical game, where NOT everyone is supposed to attack in the first line, that term can only be applied to a select few tanks.

I really wish WG to add descriptions of tanks (like, "second line support", "breakthrough tank", "scout", "sniper" etc) so people get a clue how to play them. Hopefully that will make them stop expecting Tiger or Lowe to spearhead the attack.

why not re-design the arty so that, instead of dealing direct damage on a direct hit, or near miss, they do 'crew performance damage', e.g: a shell lands near you, you're crew perform slightly less than their best %, or churn the ground making it harder to move, make them more of a 'crowd control' character class than straight DPS

it would piss a lot of people off, but it makes sense, and to anyone who says it would not be realistic or historically accurate, go play a game that cares about such things, as WoT does not

How do you separate HE shells of Arty from normal tanks... Lets let the high DMG TDs hit you with HE ammo for direct hit and you have 50% crew for the next xyz seconds while it reloads and shoot again, but with AP because your tank is fucked up without actual fuck up.

I can't understand why there is this nuking from the sky statement, because hitting with arty is nothing like that, for me that is. If I could hit 70% of time, yeah, it would be goddamn OP, but my hit are around 35-40 depending on arty in question accuracy. Add to that splash for effective damage for half the shots and I'm around 55-60% per shot dealing some damage.

And luck is a bitch, you just have to blindly hope for the dice roll being kind. But with decent knowledge your chances get higher, just like with tanks shooting to weakspot instead of enemys general direction...

The global average damage per battle on a T8 arty is lower then on every T10 tank.(Check it out on Vbaddict or so)

The difference and in my opinion the reason for the arty-crying is just the fact that you dont see the arty and you cant shoot back. When you kill a full HP T10 tank without getting damage from him he doesnt complain because he knows that he failed hard while you can be sure that an AMX 50B attacking with his ass first and thus being an oneshot for arty just wont understand that he failed. Its the same for everyone who is just standing still in the open.

One of my yesterdays battles is a nice example:Both teams on highway had 4 T7/8 artys left and I was the only tank which was left: a Maus with <100 HP.I "rushed" their base, got spotted a several times but didnt recieve a single hit because I just made some random movements.

Ofcourse an arty pro would still hit you in a Maus but everyone who complains about artys can easily decreasethe amount of pain he recieves by just learning how to play.

That is rubbish. You are using a simple match as example. I am having a plethora of high tier matches where arty enforces camping in arty safe positions, and as soon as a tank gets spotted he gets spammed with fire from three or four arties that were just waiting for an enemy tank to be revealed to them to release them from their boredom. I have also more than enough examples from matches where I went to a tactically good position, but where rocks and hills didn't provide enough cover and I got shelled into oblivion by high tier arties as soon as I got spotted, no matter how much I moved around.

Artillery ruins this game by turning it into camp fests, and if there are many arty pieces per team, as a tanker you can only hope you won't get spotted until the enemy artillery has been located by a scout and has been taken out. Such matches usually end by one side's arty taken out, allowing the other team's tanks to move freely, or by the arty being the only remaining vehicles and duking it out among themselves.

Arty in WoT sucks, period. You failtillery players just don't want to hear it. Learn to play a real tank.

And you must be the stupid guy at parties, the one who always repeats his questions three times after having received a reply already and finally giving up with a dumb look in his face and some spittle dripping from his cluelessly opened mouth, reminding everybody about your closest,relatives, the cows.

That'd be Viktor, the guy who (more or less) pays *their* wages and runs the whole damn company. Ten € on him also driving some kind of show-off car and having an unnecessarily large office desk because why the Hell not.

Oh and Anon #1 needs to go play on a highway with a blindfold due to painful levels of whiny faggotry that can only be an offense against God, Man and Nature alike.

The problem is that Victor cant spell himself as he missed capital letter. Or was it meant to be an insult?

For everyone: Russian-Polish transliteration is different form Russian-English, so it is KW and JS and it was even when commies ruled in Poland, it is that way in all wartime and history literature from that period - and commies knew best about commie tanks ;) .Why assume that English way is always better? Or always correct?

Yeah, but that's only because there's more than one billion Chinese people on this planet. The most language learned as a second language globally (So someone French, German or Chinese) will then learn english. But there's more people that speak English that use the internet than there are that speak Mandarin, and guess what? We're on the internet.

This arty rebalance wont change too much it seems.I would like to have arty which does constant dmg instead of being lucky or not. First of all no more shots which pentrates tanks and one shot them. Therefore making them more reliable. I know that there are some arty pieces allready working like this. But hightier arty mostly nukes you into oblivion or does fucking nothing. It just has to be less random but then again WG wants that also idiots can stay with about 50% WR.

And arty only does less dmg on the avg compared to "normal" tanks because its hard to do dmg when the match is too one-sided and some maps are bad for arties but therefore you get the good ones too. Still some tanks are able to perform decent in every situation.

Its not about arty being OP. Its about arty is too random and WG doesnt seem to get it.

Actually at the moment the medicore are at somewhere 46-47% due to high amount of 60%+ players... because every 60%+ means 6+ 47% players on the distribution... And the longer this drags onward the bigger the gap will get.

So WG tries to actually pull the skill on new level to actually create disparicy among players so the skill counts more instead of leveling.

Arty stays as exception to this. Just messing around with the Accuracy would been enough... but with dispersion and aimtime and reloading worsened... it will dimish difference more on arty as the good players will have to wait just bit more longer again, closer to that of noobs where as in tanks, good players can shoot earlier due to knowledge of chances against just randomly taking the pot shot by noob.

Call it just another bullshit on artys side because they get full battered nerfing while they are already below par... If WG wants more noobs on them, then be my guest... I'd rather see more talented people on the machines, because that 0-500 T92 shooting 2 shots in 15mins match because there was no green line/spot anywhere is quite sickening in comparison to the 10+ shots and 2-3k damage from only splashing the behind obvious spots noobs stay in.

ARTY is the WORST implemented tank in the game. A 45% noob can randomly one-shot your tank (in arty cover) cause he hit the only 1 cm portion of your turret which was exposed and as well a 70% pro can miss a perfectly aimed shot at a heavy charging wide open! That is BS! ATM, arty is the only tank which ALLOWS BAD players to have lucky high damage games! Second worst comes monster alpha invisibles camping TDs. RNG + HUGE ALPHA DMG = NOOBS favorite lottery. Make the f**** arty more accurate, increase the ROF, aim time, traverse, etc. but reduce the f**** damage!

Sadly what the above seems to show is that WG.net don't know how to write an algorithm for the truncated normal distribution http://en.wikipedia.org/wiki/Truncated_normal_distribution.

Generating a normally distributed variable then chopping off the ends is not the same.

With the 8.6 changes there is about the same chance of something landing on the very outside of the aiming circle as there is between the 80% and 100% limits, which is about 46% (almost half) of the aiming circle area. This (sorry to say) is not ... it just doesn't make sense!

At the same time this botch has made most guns so accurate we can all but ignore skills such as snapshot and smooth ride, gun laying drives. Aiming time an accuracy become minor factors in most guns.

If you were to draw the distribution they use in WoT it would look like a truncated normal but with two enormous spikes at each end to represent the frequency with which shots hit the aiming circle. Nonsense!

If it was a true truncated normal the chance of a shot landing exactly on the aiming circle would be virtually negligible, hence the reason that beyond this point it SHOULD drop to zero.

If you did a true truncate normal we could go back to the limits and parameters used in 8.5 which I quite liked and have virtually no shots hit the aiming circle.

Alternatively you could use something like the Beta(2,2) distribution http://en.wikipedia.org/wiki/Beta_distribution

Say 256 elements long to make the most of a single byte index. Each value in this table (a float array) would be a multiplier of the aiming circle radius, distributed so that the 1st element =0, indicating a dead centre shot and the 256th element 1.0 indicating a shot on the aiming circle and the other values in between would contain appropriate values between 0 and 1 in order, starting low and gradually building to 1 such that they describe the curve of the desired distribution.